Unit 3: Cellular Energetics
Name: Jayden Jumbo, Euan Morton Period:5th
Cell Respiration
1.Give the formula
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O
2.What organisms undergo glycolysis and where does it occur.
All organisms, including both prokaryotes and eukaryotes, undergo glycolysis. It occurs in
the cytoplasm of the cell.
3.What is glycolysis?
Glycolysis is the first step in breaking down glucose to extract energy. It splits one
molecule of glucose into two molecules of pyruvate.
4.What is chemiosmosis and where does it occur? Why not in prokaryotes?
Chemiosmosis is the process where ATP is made using the energy from a hydrogen ion
gradient. It occurs in the inner mitochondrial membrane. In prokaryotes, it does not occur
in mitochondria because they don’t have them, so it happens in their cell membrane.
5.Describe the basic structure of ATP and describe the energy cycle between ADP and
ATP.
ATP is made of adenine, ribose (a sugar), and three phosphate groups. Energy is stored
in the bond between the second and third phosphate. When that bond breaks, it becomes
ADP and energy is released. Adding a phosphate back to ADP forms ATP again, storing
energy.
Glycolysis
6.Glucose is broken down into?
Glucose is broken down into two pyruvate molecules.
7.How many ATP’s are invested? What is the net yield of ATP? How many NADH are
produced?
Two ATP molecules are invested in glycolysis. The net yield is two ATP molecules. Two
NADH molecules are also produced.
8.Where does this occur?
Glycolysis occurs in the cytoplasm of the cell.
Kreb’s Cycle (aka Citric Acid Cycle)
9.What are the 2 pyruvates converted into before they can enter the citric acid cycle?
The two pyruvates are converted into two molecules of acetyl-CoA before entering the
citric acid cycle.
10.What is released in the process?
Carbon dioxide is released during this process.
11.How many ATP’s are released?
Two ATP molecules are released during the Krebs cycle, one from each acetyl-CoA.
12.How many NADH’s? Where do they go?
Six NADH molecules are produced, and they go to the electron transport chain.
13.How many FADH2’s? Where do they go?
Two FADH2 molecules are produced, and they also go to the electron transport chain.
14.In animal respiration, what happens to the CO2 that is released?
In animals, the CO2 that is released is exhaled as a waste product.
15.Where does this occur?
The Krebs cycle occurs in the mitochondrial matrix.
Electron Transport Chain
16.Why is this process called chemiosmosis or oxidative phosphorylation?
It is called chemiosmosis or oxidative phosphorylation because it uses a proton gradient
and the movement of electrons to make ATP.
17.What do the NADH and the FADH2 do for this process?
NADH and FADH2 donate electrons to the electron transport chain to help create a proton
gradient used for ATP production.
18.Draw and describe the ETC steps. Be sure to include NADH, FADH2, cytochrome
carrier proteins, H+ ions, concentration gradient, pump, ATP synthase, ADP, ATP, oxygen
as the final electron acceptor.
19.What is produced when oxygen accepts the final electons?
When water accepts the final electrons water is produced.
20.How many ATP’s are produced?
30 ATP’s are produced in the ETC, but in total 34 are produced.
21.Where does this occur?
The electron transport chain occurs within the cristae, or the inner mitochondrial matrix.
Anaerobic Respiration
22.What happens if no oxygen is present in the cell after glycolysis?
If there is no oxygen present in the cell after glycolysis then fermentation occurs by
degrading NAD+
23.What is the difference between anaerobic respiration in animals vs. anaerobic
respiration in plants, yeast, and bacteria?
The difference between anaerobic respiration vs. anaerobic respiration in plants, yeast,
and bacteria is that in animals lactic acid fermentation occurs in which pyruvate is
converted in lactate while in plants, yeast, and bacteria alcoholic fermentation occurs and
pyruvate is converted to ethanol and CO2.
24.What is another name for anaerobic respiration?
Another name for anaerobic respiration is fermentation.
Photosynthesis
25.Give the equation for photosynthesis.
6CO2+6H2O+light→C6H12O6+6O2
26.What types of organisms undergo photosynthesis?
Autotrophs undergo photosynthesis; plants, algae, and cyanobacteria.
27.What is the purpose of photosynthesis?
The purpose of photosynthesis is to convert light energy into chemical energy, glucose.
Light Reaction (Non-cyclic photophosphorylation and cyclic)
28.Provide a flowchart for the steps of the light reaction. It might be nice to draw the steps
too. Include the following terms: a. photosystem II (P680) b. primary electron acceptor d.
electron transport chain e. ADP-ATP f. Photosystem I (P700) g. Primary electron acceptor
h. Electron transport chain i. NADP-NADPH
29. Where do all these steps occur?
All of these steps occur within the thylakoid membrane of the chloroplast.
Dark Reaction
30.What is Dark Reaction (aka Calvin Cycle)
The dark reaction or calvin cycle is the process in which ATP and NADPH are used to fix
CO2 into glucose.
31.Provide a flowchart for the steps of the Calvin cycle. It might be nice to draw the steps
too. Include the following terms: a. Carbon fixation b. Rubisco c. CO2 d. RuBP e. PGA
(3C) f. Glucose (6C)
32.Where does this process take place?
This process takes place in the stroma of the chloroplast.
C4 and CAM Photosynthesis
33.What happens when there is not enough carbon dioxide entering the leaf?
If there is not enough carbon dioxide entering the leaf then photorespiration occurs in
which rubisco binds to O2 instead of CO2.
34.Explain C4 Photosynthesis. Which plants undergo C4 photosynthesis?
C4 photosynthesis is when CO2 is fixed into 4C compounds, mesophyll, then it is released
in bundle sheaths for the Calvin cycle. Plants that live in hot or dry environments such as
sugarcane or maize undergo C4 photosynthesis.
35.Explain CAM Photosynthesis. Which plants undergo CAM photosynthesis?
CAM photosynthesis is when the stomata opens at night to fix CO2 into malate, then the
Calvin cycle occurs during the day. Plants that live in arid climates such as cacti undergo
CAM photosynthesis.
